Enhanced Performance Specifications for Embankment Construction

1. Enhanced Performance SpecificationsforEmbankment Construction George Filz

2. Enhanced Performance Specificationsfor Embankment Construction • Motivation for the research • Issues to be considered • Work tasks • Schedule

3. Motivation The Traditional Approach to Earthwork • Specification: • Maximum acceptable lift thickness • Minimum acceptable relative compaction • Acceptable range of water content • Quality assurance for the owner: • Full-time observation by an experienced person • Relatively infrequent tests

4. Motivation The Problem • VDOT budget cuts and early retirements • Reductions in the number of inspectors • Reductions in the experience level of inspectors • Continued use of infrequent tests • Part-time observation by inexperienced inspectors combined with infrequent tests • VDOT cannot verify that it is receiving the quality it is purchasing • Embankments experience excessive compression and slope failures • Contract disputes occur

5. Motivation Possible Solution:Enhanced Performance Specifications • A new type of specification: • Maximum allowable embankment compression during a post-construction performance period • Maximum allowable area of slope failure during a post-construction performance period • Possible enforcement tools: • Performance bond • Removal from pre-qualified contractor list

6. Motivation Overall Goal As Stan Hite described it, the overall goal is to put as much of the work as possible under the contractor’s control, while still providing VDOT with assurance that it is receiving the intended end product. If successful, this would reduce the potential for construction disputes, maintain quality, and be achievable with VDOT’s limited resources.

7. Issues Specification Issues • Quantities to be measured • Methods of measurement • Frequency of measurement • Organization responsible for measurement • Performance period • Consequences of non-performance

8. Issues Implementation Issues • Design-build versus design-bid-build • Primary versus secondary roads • Supply of and demand for VDOT personnel depends on VDOT staffing levels and amount of VDOT construction underway • Transition from current practices to new practices • Several alternative approaches may be necessary to cover these circumstances

9. Work Tasks Work Task 1: Establish Focus Group • Andy Mergenmeier • Tom Pelnik • Stan Hite • Gale Dickerson • Ed Hoppe • David Lee

10. Work Tasks Work Task 2: Literature Review • Compendex • GeoFind • Geotechnique • SGI • USACOE • FHWA • ASCE

11. Work Tasks Work Task 3: Interview Experts • VDOT • Other DOTs • FHWA • USACOE • USBR • International contacts

12. Work Tasks Work Task 4: Reliability Calculations • Three typical VDOT embankment geometries • Ranges of material property values • Use Duncan (2000) to calculate the probability of (a) embankment compression exceeding an allowable amount and (b) slope failure • Use results as a guide for new specifications

13. Work Tasks Work Tasks 5 through 7 • Task 5: Develop draft recommendations and circulate for review • Task 6: Revise recommendations • Task 7: Prepare report

14. Schedule Project Schedule

15. Enhanced Performance Specificationsfor Embankment Construction Put as much of the work as possible under the contractor’s control, while still providing VDOT with assurance that it is receiving the intended end product.